Transmission brake



April 15, 1930. .H. B. SHIELDS 1,754,286

TRANSMI SS ION BRAKE Original Filed March 23, 1926 2 Sheets-Sheet 1 April 15, 1930. H. B. SHIELDS 1,754,286

TRANSMI SS ION BRAKE Original Filed March 23. 1926 2 Sheets-Sheet 2 avweuto'c Patented Apr. 15, 1930 UNITED STATES PATENT OFFICE HENRY B. SHIELDS, OIE FREEPORT, NEW YORK, ASSIGNOR TO INTERNATIONAL MOTOR COMPANY, OF NEW YORK, N. 'Y., A CORPORATION OF DELAWARE' TRANSMISSION BRAKE Original application filed March 23, 1926, Serial No. 96,677. Divided. and. this application filed November 21, 1927. Serial no. 234,588.

This application is a division of my 00- pending application Serial No. 96,677 filed March 23, 1926 in which there is set forth'and described a transmission or change speed mechanism for self-propelled vehicles of such a construction as to overcome the difficulties usually encountered in shifting gears. According to the invention disclosed in my said copending application the cooperating gears of various, ratios are carried respectively upon a countershaft and a driven shaft journaledin a suitable transmission housing as is customary, but instead of one of the sets of gears being slidably mounted upon one of the shafts for, engagement selectively with the cooperating gears upon the other a shaft, the respective pairs of gears are so mounted as to be always in mesh and the gears upon one shaft, for instance the driven shaft, are carried upon aseries of concentric sleeves, the selective rotation of the respective sleeves being effected from the driving shaft through theinstrumentality of clutching mechanism of a simplified and improved design. There isalso set forth in my said copending applicationv(and with this the present application isspecifically concerned) a means for braking or retarding the propeller shaft by utilizing the constantly meshed gears as a plurality of fluid pumps,,the resistance to the flow of fluid onwhat may be called the outlet side of such pumps retarding the rotation of the" gearing, and hence the propeller shaft, and thus braking the vehicle. u

A preferred embodiment of the invention has been illustrated in the accompanying drawings to which reference should be had in connection with the following detailed decated by the line 2-2 in Figure 1 and looking in the direction of the arrows and showing the utilization of the enmeshing gears as fluid pumps for the purpose ofefiecting a 1'8? tardation of the rotation thereof to brake the vehicle. a Figure 3 is a longitudinal sectional view taken in the plane indicated by the line 33 in Figure 2 and looking in the direction of the arrows. i

Referringfirst-to Figurel the change speed mechanism is illustrated as including acountershaft a and a driven shaft 6 which is journaled in a recessed end a of a shaft 0 rotated by the prime mover. The propeller shaft is, of course, operativelyconnected, preferably by a universal joint, with the right-hand end as viewed in Figure 1 of the driven shaft 6. The drive is eifected in general from the driv ing shaft 0 through a suitably proportioned pair ofrgears to the countershaft a and from the countershaft by another suitably proportioned pair of gears including the gear b to the driven shaft 6. It is proposed to afford three different speeds in a forward direction as well as a direct drive and a reverse drive by the transmission according to the present invention. To this end three gears of dif ferent diameters d, e and f, respectively, are illustrated as carried with the driven shaft 1) and asmeshing with the respective gears cl, 6 and f on the countershaft. Gears d, e, f and a gear a meshing with the gear b, are keyed to the countershaft a. Preferably, these gears are formed on a unitary carrier member g keyed as at g, g to the countershaft a. Each of the gears d, e and f are carried upon respective concentric sleeves (Z 6 and f surrounding shaft band these sleeves are of such length as to extend outwardly beyond the front wall h of the transmission housing for selective engagement with the driving shaft 0'. a r y The reverse drive is effected by a' gear 2' on the shaft 6 rotating gear 71 on countershaft 0: through the instrumentality of another gear, not shown, in the usual manner.

Gear 71 is also carried upon a concentric sleeve flanges? formed. on, the end of drivingshaft 0.

and carrying a cylindrical or annular element j, having an inwardly extending flange 7" centrally thereof and carrying atits outer edge an inwardly extending flange is. J ouriintheflangesiag, j and 7c; are; a. series; of rods Z, m and n which have supported thereon in suitable fashion friction discs Z, we and n. Rods Z, on and n; are respectively connected to levers Z m and n fulcrumed as at 0* upon the bracket 0 so that through the instrumentality of one of the levers movement of-the rod'will bring one of the friction discs Z, m andn into engagementwith one ofthe-adjacent friction discs 7", e (Z or oas'the case may be, the friction disc 0 being carried upon shaft Z2 where direct drive may be effected. Thusone of the aforesaid discs may be frictionally retained in contact with flange c or its associated parts whereby the friction discs andthe corresponding concentric sleeve may be caused to'rotate in unison. The actuating mechanism for the levers Z m and n? may take any desired form. In the illustrated embodiment a plurality of concentric sleeves Z", m and n are disposed upon the end of shaft 0 and are formed with socketsto receive the end of the levers and with other sockets to receive the end of actuating fingers L, M and N. The clutching discs Z", m; and 11/ are each provided with not less than 3 rods Z, m and n and three levers Z m and n makin nine rods and nine levers evenly spaced about the face of the flange 0 This is tovinsure an even, distribution of. pressure to.the.discs.Z, m and n.

Assumin that it is desired to effect a direct drive etween the drivin shaft 0 and the driven shaft 6 lever, L will be moved to the right as viewed in Figure 1 thereby movin concentric sleeve Z that direction and e ecting movement of thelever Z about the fulcrum c 'to cause movement of. rod Z to the left carrying with it thedisc Z and clamping the disc 0 firmly a ainstthefiange 0 Disc 0 is thus frictionzfily engaged between the adjacent faces of flanges 0 and disc-Z and the two shafts 0 and? are caused to rotate in, unison.

If it is desired thatshaft: b rotate at a s veedof rotation different from that of shaft 0 this is accomplished driving through one of'the pairs of gears d, ecor f; Tothis endone ofthe fingers, say-M, is moved tozthe left moving sleeve m in that. direction and causing the movement 'ofthe, leverm about its mam to. cause movement of rod. m to the thereby cl'amping'in frictional 011'- gagement the disc 0Z between discs m and 70. Disc d is thus caused to rotate in unison with the flange 0 thereby causing rotation of the concentric sleeve d which carries the gear-d. Rotation. of gear-(Z sayin clockwise direction causes rotation of the gear cl say in counterclockwise rotation and similar rotation of thejackshaftm. Rotation of countershaft a in counterclockwise direction causes the rotation in counterclockwise direction of the gear a keyed thereon which in turn causes rotation, say in clockwise di rection of the gear 6 and; the shafts bat a speed dependent upon the ratios of the gears (Z, cZ and Z), Z). For different speeds of rotation of thepropeller shaft 6 different gear ratios are availed of as will be understood,

the pair of gears offering the desired ratio.

being rendered effective in a similar manner. It is understood that only one clutch may be engaged at one time and this will be taken: care of by the operating mechanism. It is thought from the foregoing description that the operation of the device will be apparent.

The retardation or braking of the propeller shaft b, as a means of retarding-the travel of the vehicle, is accomplished by enclosing the gears in a housing 17 which closeiy surrounds the gears as indicated in Figure 2. The housing is designed to serve'as a lubricant reservoir so that the gears turn constantly in a bath of oil and due to the form taken by the housing each pair of meshing gears may serve as a fluid pump, dawing iiuid from below and forcing it upwardly in the space 12 above the gears. Normally, the lubricant will be returned through the passages 72 to the bottom of the reservoir; If it is desired to retard the rotation of'the gears an obstruction may be placed in the passage 29 so that the flow of lubricant is re tarded and the back pressure will retard the rotation of the gearing. In the illustrated embodiment this obstruction may take the form ofa valve 9 having a passage 9; therein leading from the space 2 above the gears to thechannel 79 formed between housing 1) and the walls of the transmission housing h. Thus when valve 9 is open no obstruction is afforded the flow of lubricant from above the gearsthrough passage 39 to the reservoir below-the gears; By partly or en.- tirely" closingrthe valve Q this-flow of fluid is obstructed and the rotation of the gears retarded as has been explained.

Thus there has been provided a transmission in..which,there: are nogears to shift,.the constantly meshed. gears, being adapted. to act as fluid pumps-in the. manner described to. retard the: rotation of. the propeller shaft and thus brake the, vehicle. The. construction.as. a whole is compact and easy of manufacture andmay be. employed to take the place of theordinary flywheel,.clutch, transmission and" rear wheel brakes, when applied to vehicles having separate front wheel brakes. t

No limitation upon the spirit or scope of the invention is intended except as indicated in the following claim.

What I claim is:

In a transmission mechanism, in combination, a countershaft, a driven shaft, gears carried with the respective shafts and always meshing with each other, whereby the lubri cant may be pumped on rotation of said gears, means to cause selected gears to transmit motion to the driven shaft, a housing enclosing the gears and conforming closely to the outer extremities of the gears, a lubricant outlet in the housing, means permitting the lubricant pumped to return to the suction side of the gears, and means to restrict the flow of the lubricant.

This specification signed this 18th day of November, A. D. 1927.

HENRY B. SHIELDS. 

